An alkali liquor absorption tank for VOC waste gas treatment

Abstract

The utility model relates to waste gas treatment technical field, specifically disclose a kind of lye absorption tank for VOC waste gas treatment, including tank body and cover in the upper end of tank body cover, the sidewall below of tank body is provided with inlet pipe, the inlet pipe is vertically extended below working liquid surface to one end in tank body interior, its end is connected with the porous diffuser of horizontal arrangement, the advantage of two kinds of technology of bubbling and spraying is combined by static multilayer sieve plate structure, under the prerequisite of not relying on complex moving parts, the high efficiency, violent mixing of gas-liquid two-phase is realized, not only significantly improve the absorption efficiency and processing effect of VOC waste gas, also improve the operation reliability and durability of equipment, simultaneously reduce energy consumption and maintenance cost, its structure is compact and reasonable, operation monitoring is convenient, overall comprehensive performance has been substantially improved.

Description

Technical Field

[0001] This utility model relates to the field of waste gas treatment technology, and specifically discloses an alkaline absorption tank for VOC waste gas treatment. Background Technology

[0002] In the field of VOC waste gas treatment technology, alkaline absorption has become one of the mainstream technologies for treating acidic VOC components due to its clear reaction mechanism, simple operation, and relatively low cost. The core equipment of this method is the alkaline absorption tank. Its basic principle is to achieve the purpose of purifying the waste gas by neutralizing the acidic gases in the waste gas with alkaline solution. Currently, the absorption tank structures commonly used in the industry mainly include two basic forms: spray tower type and bubble tower type. Spray tower type absorption tanks mainly rely on a top spray system to disperse the alkaline solution, which then undergoes countercurrent contact mass transfer with the waste gas flowing upwards in the packing layer or empty tower space. Bubble tower type absorption tanks, on the other hand, introduce waste gas into the lower part of the liquid layer, where gas distributors form bubbles, allowing the gas to complete the absorption process as it passes through the liquid layer. These traditional structures, to a certain extent, achieve contact and reaction between the gas and liquid phases.

[0003] In practical engineering applications, the aforementioned existing technologies, for spray tower structures, primarily achieve mass transfer between spray droplets and rising airflow on the packing surface or in the empty tower space. This results in short contact time and a limited droplet surface area, leading to low absorption efficiency for sparingly soluble VOC components. For bubble column structures, bubbles generated at the bottom tend to merge into large bubbles during their ascent, causing a rapid decrease in the gas-liquid contact surface area and a decline in mass transfer efficiency. Furthermore, the single upward bubble path creates a significant "channeling" phenomenon within the tank, resulting in slow liquid turnover in some areas, forming dead zones and severely impacting the overall treatment effect. Utility Model Content

[0004] This invention proposes an alkaline absorption tank for VOC waste gas treatment, which significantly improves the absorption efficiency and treatment effect of VOC waste gas, enhances the operational reliability and durability of the equipment, and reduces energy consumption and maintenance costs. Its structure is compact and reasonable, and its operation and monitoring are convenient.

[0005] This utility model is implemented as follows: an alkaline absorption tank for VOC waste gas treatment includes a tank body and a cover that covers the upper end of the tank body. An air inlet pipe is provided below the side wall of the tank body. One end of the air inlet pipe inside the tank body extends vertically downward to below the working liquid surface, and its end is connected to a horizontally arranged porous diffuser. A spray plate is horizontally arranged above the inside of the tank, and multiple nozzles are arranged in an array at the bottom of the spray plate. A circulation pump is installed at the bottom of the tank, and the outlet of the circulation pump is connected to the spray plate through a circulation conduit. The cover is provided with a liquid inlet and a gas outlet, and the bottom of the outer wall of the tank is provided with a liquid drain outlet; Inside the tank, between the porous diffuser and the spray plate, multiple layers of horizontal sieve plates are fixedly installed at equal vertical intervals.

[0006] As a preferred embodiment of the alkaline absorption tank for VOC waste gas treatment according to this utility model, the porous diffuser is a horizontally arranged tubular structure with multiple micropores uniformly opened on its tube wall.

[0007] As a preferred embodiment of the alkaline absorption tank for VOC waste gas treatment according to this utility model, the nozzles are arranged in two staggered rings, wherein the inner ring nozzles spray vertically downwards and the outer ring nozzles spray outwards at an angle of 10°-15°.

[0008] In a preferred embodiment of the alkaline absorption tank for VOC waste gas treatment according to this utility model, the sieve holes on the two adjacent horizontal sieve plates are staggered on the vertical projection plane.

[0009] As a preferred embodiment of the alkaline absorption tank for VOC waste gas treatment according to this utility model, the horizontal sieve plate has an opening rate of 20%-35% and a sieve hole diameter of 5-15mm.

[0010] As a preferred embodiment of the alkaline absorption tank for VOC waste gas treatment according to this utility model, a gas collection hood is fixedly connected to the bottom end of the gas outlet, and the opening of the gas collection hood is directly opposite the center area of ​​the spray plate.

[0011] As a preferred embodiment of the alkaline absorption tank for VOC waste gas treatment according to this utility model, the front end face of the cover is provided with an observation window.

[0012] The beneficial effects of this utility model are: This device combines the advantages of both bubbling and spraying technologies through a static multi-layer sieve plate structure. Without relying on complex moving parts, it achieves efficient and vigorous mixing of the gas and liquid phases. This not only significantly improves the absorption efficiency and treatment effect of VOC waste gas, but also enhances the operational reliability and durability of the equipment. At the same time, it reduces energy consumption and maintenance costs. Its structure is compact and reasonable, and its operation and monitoring are convenient. The overall comprehensive performance has been substantially improved. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0014] Figure 1 This is a three-dimensional view of the overall external structure of this utility model; Figure 2 This is a front sectional view of the overall structure of this utility model; Figure 3 This is a structural diagram of the horizontal sieve plate of this utility model.

[0015] The markings in the diagram are: 1. Tank; 2. Cover; 3. Air inlet pipe; 4. Porous diffuser; 5. Spray plate; 6. Nozzle; 7. Circulation pump; 8. Circulation conduit; 9. Liquid inlet; 10. Air outlet; 11. Liquid drain; 12. Horizontal sieve plate; 13. Gas collection hood; 14. Observation window. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.

[0017] Please see Figure 1-3 An alkaline absorption tank for VOC waste gas treatment includes a tank body 1 and a cover body 2 covering the upper end of the tank body 1. An air inlet pipe 3 is provided below the side wall of the tank body 1. One end of the air inlet pipe 3 inside the tank body 1 extends vertically downward to below the working liquid surface, and its end is connected to a horizontally arranged porous diffuser 4. A spray plate 5 is horizontally arranged above the interior of the tank 1, and multiple nozzles 6 are arranged in an array at the bottom of the spray plate 5. A circulation pump 7 is installed at the bottom of the tank 1, and the outlet of the circulation pump 7 is connected to the spray plate 5 through the circulation conduit 8. The cover 2 is provided with a liquid inlet 9 and an air outlet 10, and the bottom of the outer wall of the tank 1 is provided with a liquid drain outlet 11; Inside the tank 1, between the porous diffuser 4 and the spray plate 5, multiple horizontal sieve plates 12 are fixedly installed vertically at equal intervals.

[0018] In this embodiment: the exhaust gas enters through the inlet pipe 3 and is released into a large number of fine bubbles through the porous diffuser 4 at its end, which initially increases the gas-liquid contact area. These bubbles rise under the action of buoyancy and must pass through multiple layers of horizontal sieve plates 12 continuously. Since the sieve holes of adjacent sieve plates 12 are staggered, the rising path of the bubbles is constantly disrupted, blocked and redistributed, thereby being further broken up and violently mixed with the alkaline solution, prolonging the contact time and creating a highly efficient turbulent environment. At the same time, the circulating pump 7 pumps the alkaline solution at the bottom of the tank to the top spray plate 5 through the circulating conduit 8, and sprays it downwards by the array of nozzles 6. This not only provides fresh alkaline solution, but the falling droplets also form countercurrent contact with the rising bubble group, constituting a second mixing. Finally, the purified gas is collected by the gas collection hood 13 and discharged from the gas outlet 10. The entire system achieves full mixing and reaction of alkaline solution and VOC exhaust gas through the three-stage action of "bottom microbubble diffusion, middle sieve plate cutting and turbulence, and top spray enhancement".

[0019] As a technical optimization of this utility model, the porous diffuser 4 is a horizontally arranged tubular structure with multiple micropores evenly opened on its tube wall.

[0020] In this embodiment, the porous diffuser 4 is a horizontal tube with micropores, which allows the exhaust gas to be released uniformly from multiple points with a small initial velocity, avoiding the instantaneous generation of large bubbles and forming a more widely distributed and smaller initial bubble group, laying a good foundation for subsequent thorough mixing.

[0021] As a technical optimization of this utility model, the nozzle 6 is arranged in two staggered inner and outer rings, wherein the spray angle of the inner ring nozzle 6 is vertically downward, and the spray angle of the outer ring nozzle 6 is tilted outward by 10°-15°.

[0022] In this embodiment, the nozzles 6 are set to two rings, inner and outer, with different tilt angles, to construct a cross-spraying network covering the entire cross-section of the tank 1. This eliminates spray dead zones, ensures that the alkaline solution can evenly cover each layer of horizontal sieve plates 12, and fully contact the rising airflow, thereby improving spraying efficiency and coverage.

[0023] As a technical optimization of this utility model, the sieve holes on two adjacent horizontal sieve plates 12 are staggered on the vertical projection plane.

[0024] In this embodiment, the sieve holes of adjacent horizontal sieve plates 12 are staggered in the vertical direction, forcing the upward bubble flow to change direction in order to pass through, generating strong shear and turbulence, effectively breaking up the merging bubbles and greatly enhancing the mass transfer process.

[0025] As a technical optimization of this utility model, the opening rate of the horizontal sieve plate 12 is 20%-35%, and the sieve hole diameter is 5-15mm.

[0026] In this embodiment, the opening ratio of the horizontal sieve plate 12 is 20%-35%, and the sieve hole diameter is 5-15mm. While ensuring sufficient opening area to reduce airflow resistance, it can also provide sufficient plate structure to effectively cut and disturb bubbles.

[0027] As a technical optimization of this utility model, an air collection hood 13 is fixedly connected to the bottom end of the air outlet 10, and the opening of the air collection hood 13 is directly facing the central area of ​​the spray plate 5.

[0028] In this embodiment, a gas collection hood 13 is set below the gas outlet 10 with its opening facing the center area of ​​the spray plate 5. This allows for more concentrated and stable collection of the treated gas, avoiding disorderly accumulation of gas at the top of the tank. It also helps to gather unreacted small bubbles, allowing them to come into contact with the spray droplets again, thus improving the efficiency of gas collection and secondary treatment.

[0029] As a technical optimization of this utility model, the front end face of the cover 2 is provided with an observation window 14.

[0030] In this embodiment, operators are provided with a window to directly observe the liquid level, spray status, and foam condition in the tank without opening the cover, which facilitates daily inspection and operation monitoring and improves the safety and convenience of equipment operation.

[0031] The working principle and usage process of this utility model are as follows: First, a certain amount of alkaline solution is injected into the tank 1 through the inlet 9, and the circulation pump 7 is started. After the liquid level reaches the working height, VOC waste gas is introduced from the inlet pipe 3. The end of the pipe is submerged in the porous diffuser 4, which disperses the waste gas into a dense group of bubbles. These bubbles move upward under the action of buoyancy and pass through multiple horizontal sieve plates 12 in sequence. The horizontal sieve plates 12 continuously cut, merge and redistribute the bubbles and mix them violently with the downstream liquid. At the same time, the circulation pump 7 transports the alkaline solution at the bottom of the tank to the top spray plate 5 through the circulation conduit 8. The solution is sprayed evenly downward through the nozzle 6, forming a countercurrent contact with the rising bubbles to further complete the absorption reaction. The purified gas continues to rise, is collected by the gas collection hood 13 and discharged from the outlet 10. The waste alkaline solution that participated in the reaction is periodically discharged from the drain 11.

[0032] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0033] However, the above description is merely a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. An alkaline absorption tank for VOC waste gas treatment, comprising a tank body (1) and a cover (2) covering the upper end of the tank body (1), characterized in that: An air inlet pipe (3) is provided below the side wall of the tank (1). One end of the air inlet pipe (3) is located inside the tank (1) and extends vertically downward to below the working liquid surface. Its end is connected to a horizontally arranged porous diffuser (4). A spray plate (5) is horizontally arranged above the inside of the tank (1), and a plurality of spray nozzles (6) are arranged in an array at the bottom of the spray plate (5). A circulation pump (7) is provided at the bottom of the tank (1), and the outlet of the circulation pump (7) is connected to the spray plate (5) through a circulation conduit (8). The cover (2) is provided with a liquid inlet (9) and an air outlet (10), and the bottom of the outer wall of the tank (1) is provided with a liquid drain outlet (11). Inside the tank (1), between the porous diffuser (4) and the spray plate (5), multiple horizontal sieve plates (12) are fixedly installed vertically at equal intervals.

2. The alkaline absorption tank for VOC waste gas treatment according to claim 1, characterized in that: The porous diffuser (4) is a horizontally arranged tubular structure with multiple micropores evenly distributed on its tube wall.

3. The alkaline absorption tank for VOC waste gas treatment according to claim 1, characterized in that: The nozzles (6) are arranged in two staggered rings, with the inner ring nozzles (6) spraying vertically downwards and the outer ring nozzles (6) spraying outwards at an angle of 10°-15°.

4. The alkaline absorption tank for VOC waste gas treatment according to claim 1, characterized in that: The sieve holes on the two adjacent horizontal sieve plates (12) are staggered on the vertical projection plane.

5. An alkaline absorption tank for VOC waste gas treatment according to claim 1, characterized in that: The horizontal sieve plate (12) has an opening rate of 20%-35% and a sieve hole diameter of 5-15mm.

6. The alkaline absorption tank for VOC waste gas treatment according to claim 1, characterized in that: The bottom end of the air outlet (10) is fixedly connected to an air collecting hood (13), and the opening of the air collecting hood (13) is directly facing the central area of ​​the spray plate (5).

7. An alkaline absorption tank for VOC waste gas treatment according to claim 1, characterized in that: The front end face of the cover (2) is provided with an observation window (14).

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